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Amphibious landings and small boat operations are normally conducted only in benign wave conditions. An unexpected encounter with an isolated freak wave may damage equipment and prevent mission accomplishment. This study examines the occurrence of unusually large waves using data sets obtained with bottom mounted pressure sensors and wave buoys in the DUCK 94, SHOWEX, and SAX 04 experiments. All of the experiments include wave records from high energy events. After correcting the raw pressure data for hydrodynamic attenuation over the water column, the statistics of wave heights were evaluated and compared with the theoretical Rayleigh distribution of a narrow-band linear wave field. Observations from deep water sites follow the Rayleigh distribution well, even in extreme sea states, indicating that strong nonlinearity does not have a major effect on wave height statistics. However, during high energy events at shallow water sites, there are significantly less measured wave heights in the right-hand tail of the distribution of wave heights than the theoretical Rayleigh distribution would predict. These results show that waves become more homogeneous in height as they propagate into shallower water, possibly owing to breaking and nonlinear effects. While the observed wave statistics do not suggest a frequent occurrence of freak waves, isolated large waves were indeed observed, even in benign conditions. Further studies are needed to assess their risk to Navy operations.

Leung Chun Kit = 湍流對流中速度漲落量之標度律與間歇性 / 梁振傑. / Thesis submitted in: 31st October, 2003. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 69-71). / Text in English; abstracts in English and Chinese. / Leung Chun Kit = Tuan liu dui liu zhong su du zhang luo liang zhi biao du lü yu jian xie xing / Liang Zhenjie. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Rayleigh-Benard Convection Experiment --- p.6 / Chapter 2.1 --- Rayleigh-Benard convection --- p.6 / Chapter 2.2 --- Experimental measurements --- p.7 / Chapter 3 --- Probability Density Functions of Velocity Differences --- p.10 / Chapter 3.1 --- Important time scales --- p.11 / Chapter 3.2 --- PDF calculation --- p.13 / Chapter 3.3 --- Results --- p.14 / Chapter 4 --- Characterization of Velocity Intermittency --- p.23 / Chapter 4.1 --- SL hierarchy for the velocity fluctuations --- p.23 / Chapter 4.2 --- Checking SL hierarchy --- p.24 / Chapter 4.3 --- Results --- p.25 / Chapter 5 --- The Most Intense Velocity Structures --- p.45 / Chapter 5.1 --- The most intense velocity structures and the parameters a and b --- p.45 / Chapter 5.2 --- Estimating the parameters a and b --- p.46 / Chapter 5.3 --- Results --- p.47 / Chapter 5.4 --- Checking a conjecture --- p.63 / Chapter 6 --- Conclusion --- p.67 / Bibliography --- p.69

Lam Siu = 高普朗特數湍流對流的實驗硏究 / 林霄. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 97-100). / Text in English; abstracts in English and Chinese. / Lam Siu = Gao pu lang te shu tuan liu dui liu de shi yan yan jiu / Lin Xiao. / Abstract (in English) --- p.i / Abstract (in Chinese) --- p.ii / Acknowledgements --- p.iii / Table of Contents --- p.iv / List of Figures --- p.vi / List of Tables --- p.ix / Chapters / Chapter I. --- Introduction --- p.1 / Chapter II. --- Turbulent Rayleigh-Benard Convection --- p.5 / Chapter 2.1 --- Rayleigh-Benard Convection --- p.5 / Chapter 2.2 --- The Convection Equations --- p.6 / Chapter 2.3 --- The parameters --- p.7 / Chapter 2.4 --- Recent Developments --- p.9 / Chapter 2.4.1 --- Heat Transport --- p.9 / Chapter 2.4.2 --- Large-scale Circulation and thermal Plumes --- p.11 / Chapter 2.4.3 --- Boundary Layers --- p.12 / Chapter III. --- Experimental Setup and Methods --- p.15 / Chapter 3.1 --- The Apparatus --- p.15 / Chapter 3.2 --- The Working Fluids --- p.18 / Chapter 3.3 --- Thermal Measurements --- p.23 / Chapter 3.4 --- Flow Visualization --- p.26 / Chapter IV. --- Heat Transport in Turbulent Convection --- p.29 / Chapter 4.1 --- The Non-Boussinesq Effect --- p.30 / Chapter 4.2 --- Experimental Results --- p.34 / Chapter 4.2.1 --- 1-Pentanol --- p.35 / Chapter 4.2.2 --- Triethylene Glycol --- p.36 / Chapter 4.2.3 --- Results from Dipropylene Glycol --- p.37 / Chapter 4.3 --- Discussion on the Results --- p.38 / Chapter 4.4 --- Summary --- p.43 / Chapter V. --- Local Temperature Measurements --- p.45 / Chapter 5.1 --- Temperature Time Series and Histograms --- p.45 / Chapter 5.2 --- Mean Temperature Profiles and Thermal Boundary Layers --- p.55 / Chapter 5.3 --- RMS Profiles --- p.58 / Chapter 5.4 --- Skewness Profiles --- p.65 / Chapter 5.5 --- Summary --- p.68 / Chapter VI. --- Measurements on the Viscous Boundary Layers --- p.70 / Chapter 6.1 --- Power Spectrum --- p.70 / Chapter 6.2 --- Two-Probe Cross-correlation --- p.76 / Chapter 6.3 --- Laser Light Scattering --- p.84 / Chapter 6.4 --- Summary --- p.90 / Chapter VII --- . Conclusions --- p.93 / References --- p.97

Chau Kwok Leung = 對流湍流中條件溫度結構函數之硏究 / 周國良. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves [93]-94). / Text in English; abstracts in English and Chinese. / Chau Kwok Leung = Dui liu tuan liu zhong tiao jian wen du jie gou han shu zhi yan jiu / Zhou Guoliang. / Abstract --- p.i / Abstract (Chinese Version) --- p.ii / Acknowledgement --- p.iii / Table of contents --- p.iv / List of figures --- p.v / List of tables --- p.xiii / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Rayleigh Benard experiments --- p.6 / Chapter 2.1 --- Rayleigh-Benard Experiment --- p.6 / Chapter 2.2 --- Rayleigh-Benard Convection using Helium --- p.8 / Chapter 2.3 --- Rayleigh-Benard Convection Experiment using water --- p.9 / Chapter 2.4 --- Passive Temperature Measurements in a Wind Tunnel Experiment --- p.10 / Chapter 3 --- Conditional Probability density function of the Temperature Differences --- p.11 / Chapter 3.1 --- Approximation of locally averaged temperature dissipation rate --- p.12 / Chapter 3.2 --- Conditional PDF for r < Tb --- p.14 / Chapter 3.3 --- Conditional PDF for r > Tb --- p.18 / Chapter 4 --- Conditional Statistics of Temperature Difference --- p.26 / Chapter 4.1 --- Distribution of In xT --- p.26 / Chapter 4.2 --- XT-dependence of 〈\TT\P\XT〉 --- p.28 / Chapter 4.2.1 --- Xr-dependence for small T --- p.28 / Chapter 4.2.2 --- XT dependence for large T --- p.31 / Chapter 4.3 --- "m(T,P)" --- p.39 / Chapter 4.4 --- Consequence of the Standard Gaussian Conditional PDF for T >Tb --- p.53 / Chapter 4.5 --- c(T，p) --- p.57 / Chapter 4.5.1 --- T>Tb --- p.60 / Chapter 4.5.2 --- T>Tb --- p.64 / Chapter 5 --- Height dependence of Conditional Temperature Structure Function --- p.69 / Chapter 5.1 --- Determination of rc and Td --- p.69 / Chapter 5.2 --- Height dependence of Conditional Temperature Structure Function --- p.72 / Chapter 6 --- Discussion --- p.78 / Chapter 6.1 --- Comparison with passive measurement --- p.78 / Chapter 6.2 --- Pr-dependence of Conditional PDF on XT --- p.87 / Chapter 7 --- Conclusion --- p.90 / Bibliography --- p.94

by Ma Kin Lok. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 93-95). / Text in English; abstract also in Chinese. / by Ma Kin Lok. / Acknowledgements --- p.i / Abstract --- p.ii / Abstract (Chinese version) --- p.iv / Contents --- p.v / List of Figures --- p.vii / List of Tables --- p.ix / Chapter Chapter 1. --- Introduction --- p.1 / Chapter Chapter 2. --- Experimental setups and Coherent structures --- p.10 / Chapter 2.1 --- Experimental setup for turbulent convection using helium --- p.10 / Chapter 2.2 --- Experimental setup for turbulent convection using water --- p.12 / Chapter 2.3 --- Coherent structures in turbulent convection --- p.13 / Chapter Chapter 3. --- Statistics in turbulent convection --- p.16 / Chapter 3.1 --- Statistics versus Rayleigh number and height --- p.16 / Chapter 3.1.1 --- Time series of normalized temperature fluctuations --- p.17 / Chapter 3.1.2 --- PDF of normalized temperature fluctuations --- p.18 / Chapter 3.1.3 --- q(x) and r(x) --- p.21 / Chapter 3.2 --- Statistics versus height --- p.25 / Chapter 3.2.1 --- Time series of normalized temperature fluctuations --- p.25 / Chapter 3.2.2 --- PDF of normalized temperature fluctuations --- p.28 / Chapter 3.2.3 --- Skewness and flatness of normalized temperature fluctuations --- p.32 / Chapter 3.2.4 --- q(x) and r(x) --- p.33 / Chapter Chapter 4. --- Decomposition of the helium data --- p.40 / Chapter 4.1 --- Method of study for decomposition --- p.41 / Chapter 4.2 --- Effects of the decomposition on P(x) --- p.44 / Chapter 4.3 --- Modeling of coherent structures by average peaks --- p.46 / Chapter 4.4 --- The two conditional averages of the average peaks --- p.52 / Chapter 4.5 --- Effects of the peaks on PDF --- p.57 / Chapter Chapter 5. --- Statistics of Temperature Dissipation Rate --- p.62 / Chapter 5.1 --- She and Leveque's model for energy dissipation rate --- p.62 / Chapter 5.2 --- Limits of moments of temperature dissipation rate --- p.66 / Chapter 5.3 --- Scaling of moments of temperature dissipation rate --- p.68 / Chapter Chapter 6. --- Conclusions --- p.37 / Appendix A. The relation between Nu and λth --- p.89 / Appendix B. The algorithm of filtering the peaks --- p.90 / Appendix C. Effect of normalization on the conditional averages --- p.91 / Bibliography --- p.93

自然界中存在很多的湍流熱對流現象。他們對於工業，科學與技術有著非常重要的影響。在本論文中我們利用多温度探头的技术研究了湍流熱對流的理想模型-湍流瑞利-伯納德對流中的大尺度環流在高普朗特數下的動力學特性。 / 實驗中，我们利用水和電子液體FC77 作為工作物質，獲得了普朗特數Pr 從5.3 到19.4. 瑞利數Ra 範圍8.3 × 10⁸ 2.94 × 10¹¹.我們用了一個寬高比Γ 為1 的圓柱形對流槽來研究大尺度環流的動力學特性。我們發現，在高普朗特數的時候，大尺度環流仍然是一個single roll. 這個與我們期望的是一樣的。大尺度環流的強度δ 的概率密度函數是一個高斯分佈。但是左邊的尾巴可以用一個指數函數來描述。我們也觀察到了大尺度環流傾向於呆在一個特定的角向位置。我們還發現，大尺度流動的角向運動具有擴散運動的特性。但是，用FC77 作為工作物質時，這個角向運動的擴散係數比用水作為工作物質時小兩個量級。實驗中測量到的雷諾數Re 和瑞利數Ra 之間的標度率與之前的實驗結果相符合。同時這個標度率也和Grossman-Lohse 模型的預測相符合。 / 大尺度流動豐富的動力學特性，比如說流動停止，流向反轉，扭轉還有平移振盪以及流動模式轉換，都可以在高普朗特數的時候觀察到。比較有趣的是我們發現流動停止在一個三維系統中既不依賴於Ra, 又不依賴於Pr. 這個結果和二維的瑞利-伯納德對流完全不同。 / Turbulent thermal convection is of tremendous importance to many areas of science, technology as well as the environment. In this thesis, the dynamics of the large-scale circulation (LSC) in turbulent Rayleigh-B´enard convection, which is an idealised model to study turbulent thermal convection problem, is investigated using the multi-thermal probe technique in the high Prandtl number Pr regime. / Using two kinds of working fluids, namely water and Fluorinert FC77, we achieved Pr from 5.3 to 19.4 and Rayleigh number Ra from 8.3×10⁸ to 2.94×10¹¹. The dynamics of the LSC is measured in an aspect ratio unity convection cell. It is found that the LSC in the high Pr regime is a single roll structure as expected. The probability distribution of the flow strength δ is a Gaussian distribution function with exponential tail to the left. The preferred orientation is also observed, which is revealed by the PDF of azimuthal orientation θ of the LSC. The azimuthal motion of the LSC is a diffusive process, which is the same as previous studies. However, we found that the diffusivity of the angular speed using FC77 as the working fluid is two orders smaller than using water as working fluid. The scaling of the measured Reynolds number Re number based on the oscillation frequency of the LSC with respect to Ra is in good agreement with previous experimental results and also Grossman-Lohse model prediction. / The abundant dynamical features of the LSC, such as cessations, flow reversals, torsional and sloshing oscillations and flow mode transitions are also observed in the high Pr regime. One surprising finding is that the cessation frequency of the LSC ,based on the statistics of the mid-height level of thermistors, is independent of both Ra and Pr, which is quite different from the (quasi) two-dimensional turbulent Rayleigh-B´enard convection. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Xie, Yichao = 高普朗特數瑞利-伯納德對流中大尺度環流動力學特性研究 / 謝毅超. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 53-57). / Abstracts also in Chinese. / Xie, Yichao = Gao pu lang te shu Ruili-Bonade dui liu zhong da chi du huan liu dong li xue te xing yan jiu / Xie Yichao. / Abstract --- p.ii / Acknowledgement --- p.iv / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Natural convection and Rayleigh-B´enard convection --- p.1 / Chapter 1.2 --- Governing equation and control parameters of RB Convection --- p.2 / Chapter 1.3 --- The large-scale circulation in turbulent RB convection --- p.4 / Chapter 1.4 --- Motivation and organisation of this thesis --- p.6 / Chapter 2 --- Experimental Setup and Measurement Techniques --- p.7 / Chapter 2.1 --- The convection cell --- p.7 / Chapter 2.1.1 --- The conduction plate and sidewall --- p.7 / Chapter 2.1.2 --- Cooling and heating system --- p.7 / Chapter 2.1.3 --- Level of the convection system --- p.7 / Chapter 2.2 --- The thermistor and it’s calibration --- p.9 / Chapter 2.3 --- Multi-thermal-probe technique --- p.10 / Chapter 2.4 --- Data analysis method --- p.12 / Chapter 2.4.1 --- Sinusoidal fitting method (SF method) --- p.12 / Chapter 2.4.2 --- Temperature extrema extraction method (TEE method) --- p.13 / Chapter 2.5 --- Physical properties of FC77 --- p.14 / Chapter 2.6 --- Other equipment --- p.15 / Chapter 3 --- Dynamics of LSC in high Pr turbulent RBC --- p.16 / Chapter 3.1 --- Background --- p.16 / Chapter 3.2 --- Experimental setup and data analyse method --- p.18 / Chapter 3.3 --- Results and discussion --- p.19 / Chapter 3.3.1 --- General features of the LSC --- p.19 / Chapter 3.3.2 --- Statistics of the angular speed --- p.23 / Chapter 3.3.3 --- Reynolds number Re --- p.30 / Chapter 3.3.4 --- Cessations, reversals and flow mode transitions --- p.34 / Chapter 3.3.5 --- Torsional and sloshing motions of the LSC --- p.42 / Chapter 3.4 --- Summary --- p.48 / Chapter 4 --- Conclusion and outlook --- p.51 / Chapter 4.1 --- Conclusion --- p.51 / Chapter 4.2 --- Outlook --- p.51 / Bibliography --- p.53

Chui Ka Wing = 湍流對流中速度及溫度漲落量之關係 / 徐家榮. / Thesis submitted in: August 2002. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 77-78). / Text in English; abstracts in English and Chinese. / Chui Ka Wing = Tuan liu dui liu zhong su du ji wen du zhang luo liang zhi guan xi / Xu Jiarong. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- The Kolmogorov 1941 Theory (K41) --- p.3 / Chapter 1.3 --- She-Leveque hierarchical structure(SLHS) --- p.4 / Chapter 1.4 --- Rayleigh-Benard convection --- p.6 / Chapter 2 --- Velocity and temperature structure functions --- p.11 / Chapter 2.1 --- The velocity measurements --- p.11 / Chapter 2.2 --- The characteristic time scales --- p.14 / Chapter 2.3 --- The validity of GESS --- p.18 / Chapter 2.4 --- The validity of SLHS and the estimated values of β --- p.22 / Chapter 3 --- Relations implied by Bolgiano scaling --- p.27 / Chapter 4 --- Correlation between temperature and velocity differences --- p.51 / Chapter 4.1 --- The correlation coefficient --- p.51 / Chapter 4.2 --- Normalized conditional average --- p.53 / Chapter 5 --- Generalized scaling between velocity and temperature struc- ture functions --- p.60 / Chapter 5.1 --- Relations between p and p --- p.70 / Chapter 5.2 --- Relation between Δpv and Δp --- p.72 / Chapter 6 --- Summary --- p.75 / Bibliography --- p.77 / Chapter A --- Derivation of Eq. (1.11) and (1.12) --- p.79 / Chapter A.1 --- Derivation of Eq.(1.11) --- p.79 / Chapter A.2 --- Derivation of Eq.(1.12) --- p.80

Chan Ho-Sun = 在粗糙表面的高普朗特數湍流對流實驗 / 陳浩新. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 69-72). / Text in English; abstracts in English and Chinese. / Chan Ho-Sun = Zai cu cao biao mian de gao Pulangte shu tuan liu dui liu shi yan / Chen Haoxin. / Abstract (in English) --- p.i / Abstract (in Chinese) --- p.ii / Acknowledgements --- p.iii / Table of Contents --- p.iv / List of Figures --- p.vi / List of Tables --- p.viii / Chapters / Chapter 1. --- Introduction --- p.1 / Chapter 2. --- Theories about the Convection --- p.7 / Chapter 2.1 --- Rayleigh-Benard convection --- p.7 / Chapter 2.2 --- The Convection Equations --- p.8 / Chapter 3. --- Setup of the Experimental Environment --- p.15 / Chapter 3.1 --- The Convection Cell --- p.15 / Chapter 3.2 --- Thermistors --- p.19 / Chapter 3.3 --- The Working Fluids --- p.22 / Chapter 3.4 --- Thermal Measurements --- p.27 / Chapter 3.5 --- Temperature Control Box --- p.28 / Chapter 4. --- Heat Transport Measurement --- p.29 / Chapter 4.1 --- Correction Procedures --- p.30 / Chapter 4.2 --- The Non-Boussinesq Effects --- p.33 / Chapter 4.3 --- Experiment Results --- p.41 / Chapter 4.3.1 --- Triethylene Glycol --- p.41 / Chapter 4.3.2 --- Dipropylene Glycol --- p.45 / Chapter 4.4 --- Discussion on the Results of Heat Transport --- p.50 / Chapter 4.5 --- Discussion on the Results of RMS Fluctuations --- p.60 / Chapter 4.6 --- The data set of pr =1400 --- p.63 / Chapter 5. --- Conclusion --- p.65 / References --- p.69

Chen Ji = 由純淨有機物質及其混合物產生的具有退極化性質的超瑞利散射的光譜研究 / 陳佶. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 91-92). / Text in English; abstracts in English and Chinese. / Chen Ji = You chun jing you ji wu zhi ji qi hun he wu chan sheng de ju you tui ji hua xing zhi de chao Ruili san she de guang pu yan jiu / Chen Ji. / Abstract --- p.i / Chhiese Abstract --- p.ii / Acknowledgments --- p.iii / Table of Contents --- p.iv / List of Figures and Tables --- p.vii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Basic Theory --- p.5 / Chapter 2.1 --- A brief introduction to nonlinear optics --- p.5 / Chapter 2.2 --- Second Harmonic Generation (SHG) --- p.7 / Chapter 2.3 --- Hyper Rayleigh Scattering (HRS) --- p.9 / Chapter 2.4 --- Comparison between Second Harmonic Generation and Hyper Rayleigh Scattering --- p.10 / Chapter 2.5 --- HRS signal from a liquid --- p.12 / Chapter 2.6 --- Methods for measuring hyperpolarizability βby HRS --- p.13 / Chapter 2.7 --- Theoretical description of the depolarization ratio in HRS for a rod-like molecule --- p.16 / Chapter 2.8 --- Organic molecules with strong quadratic nonlinearities --- p.20 / Chapter Chapter 3 --- Experimental Setup --- p.25 / Chapter 3.1 --- Introduction --- p.25 / Chapter 3.2 --- Detailed descriptions of the main componets --- p.27 / Chapter 3.2.1 --- Laser system --- p.27 / Chapter 3.2.2 --- Scattered light collection system --- p.29 / Chapter 3.2.3 --- Data acquisition system --- p.32 / Chapter 3.3 --- Basic performance tests of the experimental setup --- p.35 / Chapter 3.3.1 --- Temporal stability of the apparatus --- p.35 / Chapter 3.3.2 --- Linearity of the light detection apparatus --- p.36 / Chapter 3.3.3 --- Background noise --- p.38 / Chapter 3.4 --- Sample preparation --- p.40 / Chapter Chapter 4 --- General spectral measurements and measurement of hyperpolarizability β for some organic chemicals --- p.41 / Chapter 4.1 --- Low and high resolution HRS spectra of several common liquids --- p.41 / Chapter 4.2 --- Experimental performance test of HRS by using PNA solution --- p.45 / Chapter 4.3 --- Measurements of the first order hyperpolarizability b for Crystal Violet (CV) by a modified Internal Reference Method (IRM) --- p.50 / Chapter 4.3.1 --- Basic spectral measurement of CV --- p.50 / Chapter 4.3.2 --- Measurement of hyperpolarizability β for CV --- p.52 / Chapter Chapter 5 --- Study of coherent and incoherent hyper-Rayleigh scattering for organic chemicals --- p.57 / Chapter 5.1 --- Introduction --- p.57 / Chapter 5.2 --- Calibration of the experimental setup --- p.59 / Chapter 5.3 --- "Study of depolarization ratio of PNA solution, Nitrobenzene and CCl4" --- p.64 / Chapter 5.4 --- Further study of depolarization ratio for Nitrobenzene and its mixtures --- p.68 / Chapter 5.5 --- More studies on depolarization ratios for CC14 and Nitrobenzene --- p.79 / Chapter 5.6 --- "Spectral study of PNA solution, Nitrobenzene and its mixtures" --- p.83 / Chapter 5.7 --- Summary --- p.85 / Chapter Chapter 6 --- Conclusions --- p.88 / References --- p.91